Surface Functionalization Of Adsorptive Crosslinking Polymer And Its Properties Characterization

With the widespread production and use of pesticides,environmental problems have become increasingly prominent.The traditional pretreatment process of pesticide detection methods is complicated,and new detection methods and processing technologies are widely concerned.Therefore,the development of a kind of multifunctional materials with adsorption,detection and photodegradation functions has not only high scientific research value,but also good application prospects.Fluorescence detection is fast and convenient.Based on the solid-phase extraction materials,it will have a very high development prospect to develop a fluorescent detection method for pesticides.Perylene is a kind of representative organic semiconductor material,which has strong fluorescence characteristics and visible light absorption capacity,and can be used for the detection and degradation of organic pollutants.Amberlite XAD-2?XAD-2?is a kind of cross-linked polystyrene resin,which has strong adsorption performance and is widely used in solid-phase extraction,adsorption of organic pollutants and so on.Therefore,it is of great significance to functionalize the surface of pesticides and introduce fluorescence characteristics without affecting the adsorption capacity.XAD-2 resin is a cross-linked polystyrene resin,so the selection of graft polymer containing styrene segment is conducive to improving the interface affinity with the resin,enhancing the surface compatibility of the resin,and facilitating its surface modification.In order to immobilize perylene,we introduced acrylic acid segment into the grafted polymer.The carboxyl group on the acrylic acid segment can interact strongly with perylene containing amino group,which is helpful to improve the interface transition between perylene and polymer.In order not to reduce the adsorption performance of the functionalized resin,chitosan grafted polymer was selected to try the surface functionalization of XAD-2 resin.The results showed that the adsorption performance of the functionalized resin not only did not decrease,but also showed selective adsorption for some pesticides,which improved the selectivity.At the same time,the functionalized resin has fluorescence characteristics.When the fluorescence intensity of the resin is completely quenched after adsorption of pesticides,it is expected to further study the fluorescence detection of pesticides.Under the weak visible light and 808 nm near-infrared radiation,the functionalized resin shows obvious photoelectric characteristics.The light switch behavior shows that the modified material produces free electrons and holes under the excitation of weak light,which is expected to expand its application.Based on the fact that cucurbituril has both hydrophobic large ring cavity and hydrophilic surface properties,it is widely used in adsorption and self-assembly of pollutants.Therefore,cucurbituril is selected to replace chitosan to prepare graft polymer,and the similar surface functional improvement of XAD-2 resin is compared.The surface functionalized resin keeps the original adsorption performance and fluorescence characteristics,which is expected to be used for fluorescence detection and photodegradation of pesticides.After functionalization,the resin showed specific adsorption to some pesticides.After functionalization,the resin also showed obvious optical switching phenomenon to the weak visible light and 808 nm near-infrared light.In the aspect of surface functional modification,it is also a very effective way to construct heterogeneous nanocomposites.FeS/g-C₃N₄ nanocomposites were prepared by hydrothermal method,using chitosan grafted styrene and acrylic acid as soft templates.XAD-2 resin was functionalized by FeS/g-C₃N₄ heterostructure nanocomposites containing chitosan grafted polymer.The functionalized resin showed photocatalytic activity under weak visible light radiation,which is expected to realize the photodegradation of pesticides.After functionalization,the photoconductivity of the resin is greatly increased,which can make good use of weak visible light and near-infrared light.